@inproceedings{MuellerDannerBreidbachetal., author = {M{\"u}ller, Stefan and Danner, Christian and Breidbach, J{\"o}rg and Seidl, Markus and Hußlein, Thomas and Lauf, Wolfgang}, title = {Stochastic Modeling of Throughput Times of Supplier Parts for an Automotive Plant}, series = {Angewandte Forschung in der Wirtschaftsinformatik - Prozesse, Technologie, Anwendungen, Systeme und Management 2014: Tagungsband zur 27. AKWI-Jahrestagung vom 07. bis zum 10.09.2014 an der Oberbayerischen Technischen Hochschule Regensburg}, booktitle = {Angewandte Forschung in der Wirtschaftsinformatik - Prozesse, Technologie, Anwendungen, Systeme und Management 2014: Tagungsband zur 27. AKWI-Jahrestagung vom 07. bis zum 10.09.2014 an der Oberbayerischen Technischen Hochschule Regensburg}, publisher = {News \& Media}, isbn = {978-3-936527-38-4}, doi = {10.15771/978-3-936527-38-4}, pages = {35 -- 43 S}, abstract = {For modern production industries optimized supply of parts is a critical success factor. Especially in the automotive industry, the reliable supply of painted bodies for the fi nal assembly is essential for OEMs considering just in time or just in sequence processes. Additionally one central cost target is the avoidance of resorting for JIT/JIS processes. An essential workfl ow analysis is therefore the basis for making strategic or operational decisions such as the adjustment of the plant structure or increasing the number of products and variants manufactured simultaneously. In order to support strategic planning using simulation and planning systems, the modeling of the production process is required. This is particularly important for scheduling as no real manufacturing data is available and therefore prognosis based on the model are essential. Due to the short time and the limited human resources for a detailed modeling, it is essential to create a robust model with good accuracy and reduced complexity}, language = {en} } @inproceedings{EscherMuellerRuecketal., author = {Escher, Lukas and M{\"u}ller, Max and R{\"u}ck, Thomas and Jobst, Simon and Bierl, Rudolf}, title = {Digitaler Zwilling photoakustischer Spurengassensoren zur Prozess{\"u}berwachung}, series = {16. Dresdner Sensor-Symposium 2022: Vortr{\"a}ge}, booktitle = {16. Dresdner Sensor-Symposium 2022: Vortr{\"a}ge}, publisher = {AMA (Association for Sensors + Measurement)}, isbn = {978-3-9819376-7-1}, doi = {10.5162/16dss2022/3.3}, abstract = {Stickstoffdioxid (NO2) wird haupts{\"a}chlich durch anthropogene Verbrennungsprozesse in Verkehr und Industrie in die Umgebungsluft eingebracht [1]. Die stark reaktive, oxidative Wirkung von NO2 kann bei Exposition mit h{\"o}heren Konzentrationen Reizungen und allergische Reaktionen in den Atemwegen hervorrufen. Weiter f{\"u}hrt NO2 zur Bildung von saurem Regen, Smog und Ozon (O3) die sich ebenso negativ auf die menschliche Gesundheit und Umwelt auswirken [2,3]. Aufgrund dieser Effekte wird die Spurengaskonzentration von NO2 in der Luft in Deutschland an ausgew{\"a}hlten, verkehrsreichen Orten gemessen.}, language = {de} } @article{RueckPangerlEscheretal., author = {R{\"u}ck, Thomas and Pangerl, Jonas and Escher, Lukas and Jobst, Simon and M{\"u}ller, Max and Bierl, Rudolf and Matysik, Frank-Michael}, title = {Kinetic cooling in mid-infrared methane photoacoustic spectroscopy: A quantitative analysis via digital twin verification}, series = {Photoacoustics}, volume = {40}, journal = {Photoacoustics}, publisher = {Elsevier}, doi = {10.1016/j.pacs.2024.100652}, abstract = {This study presents a detailed quantitative analysis of kinetic cooling in methane photoacoustic spectroscopy, leveraging the capabilities of a digital twin model. Using a quantum cascade laser tuned to 1210.01 cm⁻¹, we investigated the effects of varying nitrogen-oxygen matrix compositions on the photoacoustic signals of 15 ppmV methane. Notably, the photoacoustic signal amplitude decreased with increasing oxygen concentration, even falling below the background signal at oxygen levels higher than approximately 6 \%V. This phenomenon was attributed to kinetic cooling, where thermal energy is extracted from the surrounding gas molecules rather than added, as validated by complex vector analysis using a previously published digital twin model. The model accurately reproduced complex signal patterns through simulations, providing insights into the underlying molecular mechanisms by quantifying individual collision contributions. These findings underscore the importance of digital twins in understanding the fundamentals of photoacoustic signal generation at the molecular level.}, language = {en} } @misc{LautenschlaegerLeisDendorferetal., author = {Lautenschl{\"a}ger, Toni and Leis, Alexander and Dendorfer, Sebastian and Palm, Christoph and Schreiner, Rupert and Langer, Christoph and Prommesberger, Christian and Ławrowski, Robert Damian and Dams, Florian and Bornmann, Benjamin and Navitski, Aliaksandr and Serbun, Pavel and M{\"u}ller, G{\"u}nter and Liebetruth, Thomas and Kohlert, Dieter and Pernsteiner, Jochen and Schreier, Franz and Heerklotz, Sabrina and Heerklotz, Allwin and Boos, Alexander and Herwald, Dominik and Monkman, Gareth J. and Treiber, Daniel and Mayer, Matthias and H{\"o}rner, Eva and Bentz, Alexander and Shamonin (Chamonine), Mikhail and Johansen, S{\o}ren Peter and Reichel, Marco and Stoll, Andrea and Briem, Ulrich and Dullien, Silvia and Renkawitz, Tobias and Weber, Tim and Dendorfer, Sebastian and Grifka, Joachim and Penzkofer, Rainer and Barnsteiner, K. and Jovanovik, M. and Wernecke, P. and V{\"o}gele, A. and Bachmann, T. and Pl{\"o}tz, Martin and Schliekmann, Claus and Wels, Harald and Helmberger, Paul and Kaspar, Marcel and H{\"o}nicka, M. and Schrammel, Siegfried and Enser, Markus and Schmidmeier, Monika and Schroll-Decker, Irmgard and Haug, Sonja and Gelfert, Verena and Vernim, Matthias}, title = {Forschungsbericht 2012}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-783}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7834}, pages = {64}, language = {de} } @article{FoltanDinhGruberetal., author = {Foltan, Maik and Dinh, D. and Gruber, Michael and M{\"u}ller, Thomas and Hart, C. and Krenkel, Lars and Schmid, C. and Lehle, Karla}, title = {Incidence of neutrophil extracellular traps (NETs) in different membrane oxygenators: pilot in vitro experiments in commercially available coated membranes}, series = {Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs}, journal = {Journal of artificial organs : the official journal of the Japanese Society for Artificial Organs}, doi = {10.1007/s10047-024-01486-4}, abstract = {Neutrophil extracellular traps (NETs) were detected in blood samples and in cellular deposits of oxygenator membranes during extracorporeal membrane oxygenation (ECMO) therapy and may be responsible for thrombogenesis. The aim was to evaluate the effect of the base material of gas fiber (GF, polymethylpentene) and heat exchange (HE) membranes and different antithrombogenic coatings on isolated granulocytes from healthy volunteers under static culture conditions. Contact of granulocytes with membranes from different ECMO oxygenators (with different surface coatings) and uncoated-GFs allowed detection of adherent cells and NETotic nuclear structures (normal, swollen, ruptured) using nuclear staining. Flow cytometry was used to identify cell activation (CD11b/CD62L, oxidative burst) of non-adherent cells. Uncoated-GFs were used as a reference. Within 3 h, granulocytes adhered to the same extent on all surfaces. In contrast, the ratio of normal to NETotic cells was significantly higher for uncoated-GFs (56-83\%) compared to all coated GFs (34-72\%) (p < 0.001) with no difference between the coatings. After material contact, non-adherent cells remained vital with unchanged oxidative burst function and the proportion of activated cells remained low. The expression of activation markers was independent of the origin of the GF material. In conclusion, the polymethylpentene surfaces of the GFs already induce NET formation. Antithrombogenic coatings can already reduce the proportion of NETotic nuclei. However, it cannot be ruled out that NET formation can induce thrombotic events. Therefore, new surfaces or coatings are required for future ECMO systems and long-term implantable artificial lungs.}, language = {en} } @article{PangerlMoserMuelleretal., author = {Pangerl, Jonas and Moser, Elisabeth and M{\"u}ller, Max and Weigl, Stefan and Jobst, Simon and R{\"u}ck, Thomas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {A sub-ppbv-level Acetone and Ethanol Quantum Cascade Laser Based Photoacoustic Sensor- Characterization and Multi-Component Spectra Recording in Synthetic Breath}, series = {Photoacoustics}, volume = {30}, journal = {Photoacoustics}, publisher = {Elsevier}, issn = {2213-5979}, doi = {10.1016/j.pacs.2023.100473}, pages = {1 -- 12}, abstract = {Trace gas analysis in breath is challenging due to the vast number of different components. We present a highly sensitive quantum cascade laser based photoacoustic setup for breath analysis. Scanning the range between 8263 and 8270 nm with a spectral resolution of 48 pm, we are able to quantify acetone and ethanol within a typical breath matrix containing water and CO2. We photoacoustically acquired spectra within this region of mid-infra-red light and prove that those spectra do not suffer from non-spectral interferences. The purely additive behavior of a breath sample spectrum was verified by comparing it with the independently acquired single component spectra using Pearson and Spearman correlation coefficients. A previously presented simulation approach is improved and an error attribution study is presented. With a 3σ detection limit of 6.5 ppbv in terms of ethanol and 250 pptv regarding acetone, our system is among the best performing presented so far.}, language = {en} } @incollection{WeiglMuellerPangerletal., author = {Weigl, Stefan and M{\"u}ller, Max and Pangerl, Jonas and R{\"u}ck, Thomas}, title = {Scopes and Limits of Photoacoustic Spectroscopy in Modern Breath Analysis}, series = {Breath Analysis}, booktitle = {Breath Analysis}, publisher = {Springer nature}, isbn = {978-3-031-18526-7}, doi = {10.1007/11663_2022_22}, pages = {101 -- 159}, abstract = {Photoacoustic spectroscopy is a viable tool for trace gas detection in various application fields. In recent years, this technique has been exploited more and more for modern breath analysis as well. Within this chapter, a holistic overview of photoacoustic spectroscopy is presented, while maintaining the relationship to breath analysis. Therefore, a concise description of the fundamentals of photoacoustic spectroscopy is provided. This is essential for understanding the scopes and limits of this outstanding measurement technique being described within this chapter. In the past several different types of photoacoustic measurement setups for trace gas detection have emerged, including different light sources, modulation techniques, and detection schemes. These are described shortly and advantages as well as disadvantages, especially in relation to breath analysis, are highlighted. Though being a promising sensor principle, measurement devices based on photoacoustic spectroscopy are still rare on the sensor market, especially when it comes to trace gas detection in complex gas matrices, e.g., human breath exhale. One main reason is due to possible molecular interactions influencing the relaxational behavior of the analyte altering the sensor signal. Recent results shedding light on the intricate relaxational processes within complex gas matrices are discussed in detail, providing approaches to overcome this issue. Finally, various applications of photoacoustic spectroscopy in breath analysis are described demonstrating the great potential of this technology.}, language = {en} } @article{SteigerFoltanPhilippetal., author = {Steiger, Tamara and Foltan, Maik and Philipp, Alois and M{\"u}ller, Thomas and Gruber, Michael and Bredthauer, Andre and Krenkel, Lars and Birkenmaier, Clemens and Lehle, Karla}, title = {Accumulations of von Willebrand factor within ECMO oxygenators: Potential indicator of coagulation abnormalities in critically ill patients?}, series = {Artificial Organs}, volume = {43}, journal = {Artificial Organs}, number = {11}, publisher = {Wiley}, address = {Hoboken}, issn = {1525-1594}, doi = {10.1111/aor.13513}, pages = {1065 -- 1076}, abstract = {Clot formation within membrane oxygenators (MOs) remains a critical problem during extracorporeal membrane oxygenation (ECMO). The composition of the clots-in particular, the presence of von Willebrand factor (vWF)-may be an indicator for prevalent nonphysiological flow conditions, foreign body reactions, or coagulation abnormalities in critically ill patients. Mats of interwoven gas exchange fibers from randomly collected MOs (PLS, Maquet, Rastatt, Germany) of 21 patients were stained with antibodies (anti-vWF and anti-P-selectin) and counterstained with 4 ',6-diamidino-2-phenylindole. The extent of vWF-loading was correlated with patient and technical data. While 12 MOs showed low vWF-loadings, 9 MOs showed high vWF-loading with highest accumulations close to crossing points of adjacent gas fibers. The presence and the extent of vWF-fibers/"cobwebs," leukocytes, platelet-leukocyte aggregates (PLAs), and P-selectin-positive platelet aggregates were independent of the extent of vWF-loading. However, the highly loaded MOs were obtained from patients with a significantly elevated SOFA score, severe thrombocytopenia, and persistent liver dysfunction. The coagulation abnormalities of these critically ill patients may cause an accumulation of the highly thrombogenic and elongated high-molecular-weight vWF multimers in the plasma which will be trapped in the MOs during the ECMO therapy.}, language = {en} } @unpublished{PangerlMoserMuelleretal., author = {Pangerl, Jonas and Moser, Elisabeth and M{\"u}ller, Max and Weigl, Stefan and Jobst, Simon and R{\"u}ck, Thomas and Bierl, Rudolf and Matysik, Frank-Michael}, title = {A Highly Sensitive Acetone and Ethanol Quantum Cascade Laser Based Photoacoustic Sensor: Characterization and Multi-Component Spectra Recording in Synthetic Breath}, series = {SSRN Electronic Journal}, journal = {SSRN Electronic Journal}, publisher = {Elsevier}, doi = {10.2139/ssrn.4305376}, abstract = {Trace gas analysis in breath is challenging due to the vast number of different components. We present a highly sensitive quantum cascade laser based photoacoustic setup for breath analysis. Scanning the range between 8260 and 8270 nm with a spectral resolution of 48 pm, we are able to quantify acetone and ethanol within a typical breath matrix containing water and CO2. We photoacoustically acquired spectra within this region of mid-infra-red light and prove that those spectra do not suffer from non-spectral interferences. The purely additive behavior of a breath sample spectrum was verified by comparing it with the independently acquired single component spectra using Pearson and Spearman correlation coefficients. A previously presented simulation approach is improved and an error attribution study is presented. With a 3σ detection limit of 6.5 ppbV in terms of ethanol and 250 pptV regarding acetone, our system is among the best performing presented so far.}, language = {en} } @article{HausFoltanPhilippetal., author = {Haus, Moritz and Foltan, Maik and Philipp, Alois and M{\"u}ller, Thomas and Lingel, Maximilian P. and Krenkel, Lars and Gruber, Michael and Lehle, Karla}, title = {Neutrophil extracellular traps -a potential trigger for the development of thrombocytopenia during extracorporeal membrane oxygenation}, volume = {15}, publisher = {frontiers}, doi = {10.3389/fimmu.2024.1339235}, abstract = {Neutrophil extracellular traps (NETs) have recently emerged as a potential link between inflammation, immunity, and thrombosis, as well as other coagulation disorders which present a major challenge in the context of extracorporeal membrane oxygenation (ECMO). By examining blood from ECMO patients for NETs and their precursors and correlating them with clinical and laboratory biomarkers of coagulation and inflammation, this study aims to evaluate the association between the presence of NETs in the bloodstream of ECMO patients and the development of potentially severe coagulation disorders during ECMO therapy. Therefore, blood samples were collected from healthy volunteers (n=13) and patients receiving veno-venous (VV) ECMO therapy (n=10). To identify NETs and their precursors, DNA and myeloperoxidase as well as granulocyte marker CD66b were visualized simultaneously by immunofluorescence staining in serial blood smears. Differentiation of DNA-containing objects and identification of NETs and their precursors was performed semiautomatically by a specific algorithm using the shape and size of DNA staining and the intensity of MPO and CD66b signal. Neutrophil extracellular traps and their precursors could be detected in blood smears from patients requiring VV ECMO. Compared to volunteers, ECMO patients presented significantly higher rates of NETs and NET precursors as well as an increased proportion of neutrophil granulocytes in all detected nucleated cells. A high NET rate prior to the initiation of ECMO therapy was associated with both increased iL-6 and TNF-α levels as an expression of a high cytokine burden. These patients with increased NET release also presented an earlier and significantly more pronounced decrease in platelet counts and ATIII activity following initiation of therapy compared with patients with less elevated NETs. These findings provide further indications for the development of immune-mediated acquired thrombocytopenia in ECMO patients.}, language = {en} } @article{KleinNabbefeldHattabetal., author = {Klein, C. and Nabbefeld, T. and Hattab, H. and Meyer, D. and Jnawali, G. and Kammler, Martin and Meyer zu Heringdorf, Frank-Joachim and Golla-Franz, A. and M{\"u}ller, B. H. and Schmidt, Thomas and Henzler, M. and Horn-von Hoegen, Michael}, title = {Lost in reciprocal space? Determination of the scattering condition in spot profile analysis low-energy electron diffraction}, series = {Review of scientific instruments}, volume = {82}, journal = {Review of scientific instruments}, number = {3}, publisher = {American Institute of Physics}, doi = {10.1063/1.3554305}, abstract = {The precise knowledge of the diffraction condition, i.e., the angle of incidence and electron energy, is crucial for the study of surface morphology through spot profile analysis low-energy electron diffraction (LEED). We demonstrate four different procedures to determine the diffraction condition: employing the distortion of the LEED pattern under large angles of incidence, the layer-by-layer growth oscillations during homoepitaxial growth, a G(S) analysis of a rough surface, and the intersection of facet rods with 3D Bragg conditions.}, language = {en} }